| Step |
Hyp |
Ref |
Expression |
| 1 |
|
ablsimpnosubgd.1 |
|- B = ( Base ` G ) |
| 2 |
|
ablsimpnosubgd.2 |
|- .0. = ( 0g ` G ) |
| 3 |
|
ablsimpnosubgd.3 |
|- ( ph -> G e. Abel ) |
| 4 |
|
ablsimpnosubgd.4 |
|- ( ph -> G e. SimpGrp ) |
| 5 |
|
ablsimpnosubgd.5 |
|- ( ph -> S e. ( SubGrp ` G ) ) |
| 6 |
|
ablsimpnosubgd.6 |
|- ( ph -> A e. S ) |
| 7 |
|
ablsimpnosubgd.7 |
|- ( ph -> -. A = .0. ) |
| 8 |
|
elsni |
|- ( A e. { .0. } -> A = .0. ) |
| 9 |
7 8
|
nsyl |
|- ( ph -> -. A e. { .0. } ) |
| 10 |
|
eleq2 |
|- ( S = { .0. } -> ( A e. S <-> A e. { .0. } ) ) |
| 11 |
6 10
|
syl5ibcom |
|- ( ph -> ( S = { .0. } -> A e. { .0. } ) ) |
| 12 |
9 11
|
mtod |
|- ( ph -> -. S = { .0. } ) |
| 13 |
12
|
pm2.21d |
|- ( ph -> ( S = { .0. } -> S = B ) ) |
| 14 |
|
idd |
|- ( ph -> ( S = B -> S = B ) ) |
| 15 |
|
ablnsg |
|- ( G e. Abel -> ( NrmSGrp ` G ) = ( SubGrp ` G ) ) |
| 16 |
15
|
eqcomd |
|- ( G e. Abel -> ( SubGrp ` G ) = ( NrmSGrp ` G ) ) |
| 17 |
3 16
|
syl |
|- ( ph -> ( SubGrp ` G ) = ( NrmSGrp ` G ) ) |
| 18 |
5 17
|
eleqtrd |
|- ( ph -> S e. ( NrmSGrp ` G ) ) |
| 19 |
1 2 4 18
|
simpgnsgeqd |
|- ( ph -> ( S = { .0. } \/ S = B ) ) |
| 20 |
13 14 19
|
mpjaod |
|- ( ph -> S = B ) |